Biological Properties of Hematopoietic Stem Cells: Scientific Basis for Hematopoietic Cell Transplantation

Hematopoiesis—from the Greek term for “blood making”—is the adaptive process by which mature and functional blood cells are continuously replaced over the entire lifetime of an individual. Erythrocytes, platelets, and the various subsets of leukocytes all have finite although different life spans. As a consequence, the daily production of red blood cells, platelets, and neutrophils under homeostatic conditions amounts to more than 300 billion cells.